Balanced slide-valve



' (No Model.)

E w MA V E Em RM FD .E m PM A B No. 420,495. Patented Feb. 4, 1890.

M r W INVENTDR d y/52mm) n. Finns; Phmum w, war-m m. n. c

UNITED STATES PATENT. OFFICE.

FRANCIS I. FREEMAN, OF W'ARREN, OHIO.

BALANCED SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 420,495, dated February 4, 1890.

' I Application filed December 26, 1888- Serial No. 294,593. (No model.)

resident of Warren, in the county of Trumbull and State of Ohio, a citizen of theUnited States, have invented a certain new and Improved Balanee Slide-Valve for Steam-Engines; and I do herebydeclare that the following is a full, clear, and complete description thereof.

for relieving the valve-seat of steam-engines from the steam-pressure while the valve is in operation, there being in connection therewith an adjusting wedge-shaped plate interposed between the slide valve or valves and the cover of the steam-chest for arranging the valve or valves in position With-reference to the valve-seat.

That the invention may be fully seen and understood, the following specification and accompanying drawings will be referred to, in which- Figure 1 is a central horizontal section of a steam-chest slide-valve and part of a steamcylinder provided with the improvement above referred to. Fig. 2 is a vertical section of the same on line m m, Fig. 1. detached perspective View of the said adj usting wedge-shaped plate.

Like letters of reference refer to like parts in the drawings and specification.

The invention as illustrated is applied to a double-valve engine having the steamchest located at the side thereof, the results obtained therefrom, however, being the same in any construction or design of slide-valve engine.

A represents a part of the steam-cylinder; B, the steam-chest; G the cover; D D, the slidevalves, and E E the valve-seats.

The valves D D are adjustably secured to the valve-rod F, as seen in Fig. 1, which rod is guided in either end of said chest and reciprocated by an eccentric or other means for the operation of said valves.

Through the pipe G the steam isinduced to the interior of the steam-chest B, and through the ports 11 II it is alternately admitted to and exhausted from the steam-cylinder-that is, the valves D D are alternately in open relation with the ports H H I I for Fig. 3 is av the induction to and exhausting steam from the flanges K K, which extend out from the glOWBl' side of the valve-seats E E, as seen in Figs. 1 and 2.

My improvement relates to means employed Between the outer face side of the valves D and the inner side of the cover 0 are arranged the adjusting-plates L, which plates are tapering or wedge-shaped, and having a central rib, as seen in Figs. 2 and 3, corresponding to the inclination of the inner coverfacev and the outer valve-face-that is, by means of said plates the valves D D can be held up steam-tight against their respective seats E E, excluding the steam from acting upon said valves, the pressure of which would otherwise cause a great amount of friction of the valves upon their seats and require as a consequence a corresponding amount of steam-power to move said valves.

By the arrangement of the adj usting-plates L, however, no steam-pressure can be exerted in the line of the valve-seats, except that acting upon the surrounding flanges a; but this pressure is compensated by the pressure acting upon the flanges a. in an opposite direction. The valves D D are thus entirely relieved from the existing pressure within the steam-chest. Each of the plates L L has a rib 12 extending over the rear side thereof, which rib engages in a groove 0 in the cover 0 to prevent the plate from being moved out of place by the frictional resistance of said plates and the valves. The setserews M are for the purpose of adjusting the plates L in the'required position to insure a steam-tight contact of the valves between their seats and the said plates L. By means of the bolts N the plates are securely united with the cover after once being set by means of said screws M. The holes d for the bolts N are elongated in a vertical direction, as seen in Fig. 2, to allow of the adjustment of the plates L upon the cover 0. To set or arrange the adjustingplates L in place, live steam is first admitted into the steam-chest to expand the plates to an extent commensurate with its expansion induced by the steam-heatot' the engine when in running order, to enable an accurate adjustmentof said plates to be made in relation to said valves and cover. The plates when once properly set will retain the valves in steam-tight operation for comparatively a long time; hence it is designed that the setscrews M should be removed after having the valves set and be replaced by plug-screws which will not reach them, inasmuch as a competent person should adjust said plates when the wearing-surfaces begin to allow leakage of steam past the valve-seats.

By arranging the wedge in combination with the removable cover the invention is embodied in simple and convenient form, as the incline can be accurately and easily finished and the wedge can be easilypositioned or removed. It will be noticed, also, that the wedges are arranged transversely to the direction in which the valve moves, and their position is therefore not affected by the reciprocation of the valves.

\Vhat I claim as my invention, and desire to secure by Letters Patent, is-

1. In combination, the chest 13, the valve D, the removable cover 0, having an inclined inner face, and the wedge-plate between said inner face and the valve D, the said cover having elongated openings (1, the screw-bolts passing through said openings and secured to the Wedge-plate, and means for adjusting the wedge-plate, substantially as described.

2. In combination, the chest B, the valve, the wedge-plate, said wedge-plate being inserted to bear upon the valve and being arranged transversely to the stroke of the valve, substantially as described.

In combination, the chest B, having a groove in one side, the valve, and the wedge plate interposed between said valve and the side of the chest, said wedge having a rib adapted to the groove in the chest, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

FRANCIS I. FREEMAN.

\Vitnesses:

J. P. ABBOTT, W. II. B'URRIDGE. 

